Glossary

Framed construction in which the loads are taken by cross-walls of concrete or brick.

Cross-window

A window with one mullion one transom, forming a cross-shape.

Crossing

In a church, the central space at the junction of the nave, chancel and transepts. Crossing arch: an arch spanning piers at a crossing. Crossing tower: a tower above a crossing.

Crown

The upper part of an arch or vault.

Crown-plate

Central roof-timber which carries collar-beams and is supported by crown-posts. Also called a collar purlin.

Crown-post

A vertical timber in a roof structure, set centrally on a tie-beam and supporting a collar purlin, with longitudinal braces to it. In an open truss, additional braces may rise laterally to the collar-beam; in a closed truss they may descend to the tie-beam.

Crowsteps

Squared stones set like steps, e.g. on a gable. In Scotland also called corbiesteps.

Crucks

(lit. crooked): Pairs of inclined timbers (blades), usually curved, set at bay-length intervals in a building; they support the roof timbers and, in timber buildings, also support the walls. Base crucks have blades rising from ground level to a tie-beam or collar-beam which supports the roof timbers. Full crucks have blades rising from ground level to the apex of the roof, serving as the main members of a roof truss. Jointed crucks have blades formed from more than one timber; the lower member may act as a wall-post; it is usually elbowed at wall-plate level and jointed just above. Middle crucks have blades rising from halfway up the walls to a tie or collar-beam. Raised crucks have blades rising from halfway up the walls to the apex. Upper crucks have blades supported on a tie-beam and rising to the apex.

Crypt

Underground or half-underground area, usually below the east end of a church. Ring crypt: corridor crypt surrounding the apse of an early medieval church, often associated with chambers for relics.

Cupola

(lit. dome): Especially, a small dome on a circular or polygonal base crowning a larger dome, roof, or turret. Also (Scots) a small dome or skylight as an internal feature, especially over a stairwell.